It is often desirable to suspend ceilings from overhead structures such as roofs or higher floors in order to provide a smaller space to conserve the costs of space heating and cooling and for aesthetics. For example, the basements of homes commonly have a multi-paneled ceiling suspending from overhead joists. In other cases island ceilings are suspended beneath higher ceilings and roofs for purely aesthetic reasons. Commercial buildings, such as retail stores, also commonly have suspended ceilings. Often these form the top of a refrigerated space such as a walk-in cooler in which cases the ceilings are insulated. Exemplary of such suspended ceilings are those shown in U.S. Pat. Nos. 3,736,012, 3,898,782, 4,272,928, 4,736,564, 4,744,188 and Re. 31,528.
Suspended ceilings are commonly comprised of a grid like frame which is suspended by a set of wires from an overhead structure such as the roof of a building. The grid like frame has lower flanges which are oriented horizontally upon which panels may be individually set and supported. Thermally insulated ceilings however are not well-suited for support from a grid like frame. This is because they are constructed to be interfitted sequentially in tongue and groove fashion so that they are well insulated at their junctures. Nevertheless, thermally insulated panels, which normally have an expanded foam polyurethane or polystyrene core that is overlaid by metal sheets, must be centrally supported to prevent sagging.
Heretofore, thermally insulated, multi-panel suspension ceilings have been suspended by the means of clips sandwiched between the tongues and grooves of adjacent panels mated together in tongue and groove fashion. Exemplary of such is the clip 10 shown in FIG. 2 of the drawing which is shown mounted uprightly flushly over the tongue 11 of an insulated ceiling panel 12. An unshown wire extends upwardly from the upper tab of the clip inserts. After the clip has been placed as shown in FIG. 2 a mating panel formed with a groove is placed in abutment with the tongue 11 and with its surrounding shoulders and over the clip.
The just described device and method of suspending ceilings, however, has long been beset with problems. Principal among such is the difficulty normally encountered by workers in assembling and hanging the ceilings. Without a grid frame available, and with simply the provision of independently suspended clips, panel movements encountered during the erection process easily cause the interfitted tongues and grooves of adjacent panels to become dislodged from the clip and to fall. Furthermore, even when erection has been completed the ceiling still remains susceptible to dislodgement in the event an object accidentally strikes the ceiling. This in turn can create a cascade of falling panels.
Accordingly, it is seen that a need has long existed for the provision of a suspension ceiling of the thermally insulated type which may be easily and surely erected and maintained by relatively inexpensive means. It is to the provision of such therefore that the present invention is primarily directed.